Precision Twist Drill 5996664 Cobalt Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5996664 is a cobalt screw machine length drill bit designed for drilling into hard and tough materials in production and shop environments. Built from M42 cobalt high-speed steel, it delivers heat resistance and edge retention that standard HSS bits cannot match. The bit measures 0.266 inches (17/64 inches, Letter H) in diameter with an overall length of 2-11/16 inches and a flute length of 1-1/2 inches. The 135-degree split point reduces walking and requires no center punch on most materials. Licensed machinists, tool-and-die technicians, and maintenance mechanics are the primary users of this bit.

This bit is suited for screw machine operations, CNC drilling centers, drill presses, and hand-held drilling applications where a short, rigid bit is preferred to reduce deflection. Its compact screw machine length profile provides added stiffness compared to jobber-length bits, making it a practical choice when drilling in confined setups or when hole-position accuracy is critical. The 2.5xD flute-to-diameter ratio and tapered web configuration support chip evacuation in short-hole applications on ferrous and hard non-ferrous workpieces.

Key Features

• M42 cobalt steel construction for high-performance drilling in hard and abrasive materials
• 135-degree split point reduces thrust and eliminates walking without center-punching
• Web-thinned, tapered web design promotes efficient chip removal
• Screw machine length body increases rigidity and reduces deflection versus jobber-length bits
• Straight-cylindrical shank fits standard drill chucks without adapters
• Meets ANSI standards; rated for heavy-duty use in the M42 material grade

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit compatible with standard drill chucks and collet holders accepting a straight-cylindrical shank in the 17/64-inch diameter range.

Installation Notes

Installation and use should be performed by qualified machinists or maintenance technicians familiar with rotating cutting tools. Secure the shank fully in the chuck or collet and verify runout before drilling. Always wear appropriate eye protection and follow shop safety procedures when operating drilling equipment. Coolant-through operation is not supported on this bit; use external cutting fluid on hard materials to manage heat buildup.